Sixty different strains of Streptomyces were tested for their ability to release reducing sugars form wheat straw. The most active three strains (Streptomyces mutabilis, S. chromofuscus, and S. cyanoviridis) were chosen for further studies. The action of the two enzymes laminarinase and cellulase on eight different substrates (starch, carboxymethylcellulose, wheat straw, waste paper, cellulose, mannose, glucose and glycerol) was measured. There was a decrease in the activity of laminarinase, by using different carbon sources in the following order: carboxymethylcellulose, mannose, wheat straw, waste paper, cellulose, glucose, starch and glycerol at the optimum pH 7 and temperature of 50°C. The sequence of cellulase-substrate affinity was: wheat straw waste paper, cellulose, mannose, glucose, starch, glycerol, and carboxymethylcellulose at the optimum pH 6 and temperature of 50°C. Thin layer chromatography was performed to determine the different released sugars. Hexose and pentose spots were detected.